Adding SessionTestHelper to Existing Rails Project

Hello 👋

With Rails 8, built-in authentication has been introduced. Although it seems like a small and simple step, for a developer like me who uses Devise in every project, even for basic authentication, it is a significant initiative. I am not going to talk about the Rails Authentication Generator. Instead, I’d like to focus on a small update related to testing in it.

I was very happy to use a small authentication generator for my project (bloud.me), but at that time, the documentation was not sufficient. I found a blog post about adding Rails Authentication to my tests.

I had a small method to authenticate a user, which I used in my tests whenever I needed to sign in a user.

# test/test_helper.rb
def sign_in(user, password: "password")
  post session_url, params: { email_address: user.email_address, password: }
end

class HomeControllerTest < ActionDispatch::IntegrationTest
  ....
  sign_in(user, password: "password")
  ...
end

There was a problem—I couldn’t run system tests. I needed another solution, but I couldn’t find or create one. So, I ended up removing all system tests. To be honest, I don’t really enjoy writing system tests, but that’s a topic for another blog post 😬.

One week ago, a PR was merged into the main branch of the Rails project. I am using Rails main in my project and always keep it up to date. So, I decided to update my tests according to that PR.

First of all, I needed to add SessionTestHelper to the test_helpers folder.

# test/test_helpers/session_test_helper.rb
module SessionTestHelper
  def sign_in_as(user)
    Current.session = user.sessions.create!

    ActionDispatch::TestRequest.create.cookie_jar.tap do |cookie_jar|
      cookie_jar.signed[:session_id] = Current.session.id
      cookies[:session_id] = cookie_jar[:session_id]
    end
  end

  def sign_out
    Current.session&.destroy!
    cookies.delete(:session_id)
  end
end

Update test_helper.rb

# test/test_helper.rb

...
require_relative "test_helpers/session_test_helper"
...

module ActiveSupport
  class TestCase
  include SessionTestHelper
  ...
end

I removed all my old testing helpers from the codebase and added a new one.

require "test_helper"

class HomeControllerTest < ActionDispatch::IntegrationTest
  test "..." do
    user = users(:one)
    sign_in_as(user)
    ...
  end
end

Run the test again and see the test is pass.

❤️